1. Field of the Invention
This invention relates broadly to surgical devices. More particularly, this invention relates to orthopedic instruments, such as those used to guide pins into bone.
2. State of the Art
Numerous drill guides are known for guiding drill bits into bone. Generally a drill guide is interposed between the bone and the drill, with the guide defining a directed path along a trajectory at which the hole is to be drilled into the bone. The path is typically defined by a cannulated tube or predrilled metal block. If the hole is drilled into the bone percutaneously, the guide preferably includes a tissue protector portion which is forced through the skin and seats against the bone to create a path through which the drill bit and skin are not in contact so as not to cause destruction of the surrounding dermal tissue. If it is required to drill deeper than permitted by the interposed guide, the drill bit needs to be withdrawn from the bone and the guide, the guide is then removed, and the bit is reinserted into the partially drilled hole and the hole is drilled further. After the hole is drilled, the appropriate fixator, e.g., pin, rod, or screw, is inserted into the hole.
A drill guide is used in substantially the same way when a fixation device is self-drilling and no drill bit is used. A guide with tissue protector is provided in the correct location and orientation. The fixation device is drilled through the guide into the bone. Once the device is partially inserted along the correct trajectory the guide needs to be removed from over the fixation device to permit the fixation device to fully seated. This is typically done by releasing the fixation device from the drill, removing the guide from over the fixation device, and then reattaching the drill to drive the fixation device until fully seated in bone.
In both situations, the step of drilling or device insertion is interrupted by guide removal, complicating and extending the procedure.